The paper attempts to determine which traction model best fits with experimental data for a romanian lugged tractor tire. Different models for predicting net traction and traction efficiency for off-road conditions were considered. These models assume different tire-ground pressure distributions (constant, parabolic) over the undertread area and different contact patch length calculations. Experiments were conducted and the results were compared to the theoretical data. Two of the models are the best fit with the experimental data; both models assumed a parabolic pressure distribution over the undertread. The following conclusions can be drawn:1. Several models for a lugged tire's net traction force and traction efficiency prediction were defined and investigated in order to determine the best fit with experimental results. 2. The variables taken into account were different with respect to tire undertread-ground pressure distribution (constant or parabolic) and contact patch (shear) area. 3. The contact patch length was calculated using two different tire-soil interaction models in which the vertical tire deflection under load (z_p for the first model, f₀ for the second model) was a known parameter, as it was measured previously, in a different set of experiments. 4. Comparing the calculated data with the experimental values it was seen that the variables having a parabolic pressure distribution and a constant contact area (not depending upon wheel slip) provided the best results. 5. All the variables involving a changing shear area (depending upon wheel slip) led to lower traction forces and traction efficiencies than those obtained experimentally. This led to the conclusion that either this hypothesis, although confirmed by other authors, is not suitable for the terrain conditions of the test field (medium to hard soil), or the coefficients taken into account are not suited for the testing conditions and further researches are necessary in order to determine more accurate values.